Design of SIW based diplexer for LTE applications / Nuraini Razali

This paper presents a design of planar diplexer based on substrate integrated waveguide first order single mode filters with circular cavity. The diplexer consists of two filters. The design is based on Substrate Integrated Waveguide (SIW) on a FR-4 substrate fabricated by printed circuit board technique. The dielectric constant of the substrate is 8r= 4.7. Firstly, the circular SIW filters on the TMoio mode were designed separately at 2.6 GHz and 2.7GHz. The results of the two filter are obtained with return loss less than - lOdB and insertion loss higher than -3dB. Then, the two filters are combined together to work as diplexer. The simulated design is fabricated and measured. The results of the simulation is compared to the measurement taken from fabricated hardware.